| dc.description.abstract | Aimed for reduction of light pollution and energy saving, this thesis focused on how to keep light effectively concentrated, limited, and uniform illuminated at a target region. By the motive, we proposed a novel way with high temperature down-size sintering technology and large-area impressing technology to perform a surface-structured diffuser with high transmission efficiency of 89%, obvious beam shaping effect, controllable divergence angle, and specific light pattern of uniform intensity distribution.
Based on surface-structured diffuser, we proposed a novel concept of lighting module of street light, which was composed of LED array, TIR lens array, high performance SSD, and high reflectance reflecting cavity. We assessed the luminaire performance by Monte Carlo ray-tracing for the main types of street pole arrangements, which were Central type, Zigzag type, and Single-side type. In the cases of Central type, Zigzag type, and Single-side type, the optical efficiency of lighting module were respectively 87.8%, 87.8%, and 87.2%. For the condition of a mounting height of 10 m in the cases of Central type, Zigzag type, and Single-side type, they had the central illuminance of 20 lux, 17.5 lux, and 17.9 lux, respectively; the average illuminance of 19.2 lux, 17.2 lux, and 16.2 lux, respectively; the uniformity of 0.877, 0.633, and 0.806, respectively. When the area of illuminated region was 30 m × 14 m, the optical utilization factor in Central type, Zigzag type, and Single-side type were 81%, 78.8%, and 73.6%, respectively.
Expect for high performance LED lighting module of street light, we also proposed a novel concept for an optical-adjustable luminaire with LED SSL and an SSD with surface compensation by liquid. The index matching function is useful to adjust the surface structure of the SSD so that the light pattern is adjustable to enable the luminaire more flexible. According to simulation results, light pattern is able to have continuous variation with refractive index of 1.33 to 1.5, without sacrifice of the optical efficiency.
Besides, we proposed a new way with use of a phase plate with micro-lens array to increase the shifting selectivity of hologram and to achieve higher energy efficiency. The phase plate with micro-lens array was used as a beam modulator owns inherent advantage of improving energy efficiency. Compared with a general ground glass, the simulation showed that the surface undulated structure on the SSD could perform a nearly ideal random phase distribution and the corresponding experimental results of shifting selectivity shows that the larger shifting selectivity could be observed with the SSD rather than a ground glass. The best shifting selectivity in our experimental result was less than 2 μm in both horizontal and vertical directions under the circumstance that the crystal thickness was 1 cm, the diameter of illumination area of the SSD was 2 cm, and the distance between the crystal and the SSD was 5 cm. Higher shifting selectivity will be useful to perform the theoretical capacity of holographic optical storage with random phase encoding. Different from traditional ground glass, the SSD can be well designed and duplicated in mass production process. It would be effective in holographic storage as well as in holographic data encryption.
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